Antitarnish composition



Nov. 17, 1.925-

1,561,659 T. H. LASHAR ANTITARNISH COMPOSITIO Filed April 25 1924 Cl.#Mm M INVENTOR Pm@ BY, 'g www ATTORNEYS like.

Patented Nov. 17, 1925.

THOMAS HOLMES LASHAR, 0F CHICAGO, ILLINOIS.

ANTITARNISH COMPOSITION.

To all whom t may concern.'

Be it known that I, THOMAS HOLMES LASnAR, a citizen of the UnitedStates, residing at Chicago, in the county of Cook, State of Illinois,have invented certain new and useful Improvements in AntitarnishComposition; and I do hereby declare the following to be a full, clear,and exact description of the invention, such as will enlable othersskilled in the art to which it appertains to make and use the same.

This invention reates to improvementsin the prevention of tarnish ofsilver and other metal articles, and includes an improved anti-tarnishcomposition as well as articles and structures adapted for use inkeeping silver and otherI metal articles from tarnishing.

' lThe problem of preventing or overcoming the tarnishing of silverwareand other metal articles is one of the outstanding` problems of thejewelry trade and is a problem whereever Silverware and various .othermetal articles are exposed to the atmosphere, as they are inshow-windows, show-cases, and the Even where silverware is kept inclosed show-cases, the occasional opening of the show-case for displaypurposes permits circulation of air from the outside-into the show-case,and sooner or later objectionable tarnishing fof the Silverware usuallytakes place. This objectionable tarnishing is particularly pronounced incities and towns rhaving a smoky atmosphere, where large amounts of coalare burned, because of the sulfur-containing gases which the atmospherecontains, and for which silver and other metal articles have a specialailinity. In large jewelry stores, or stores where large displays ofsilverware are found, it is customary to assign o-ne or more men to thework of polishing silverware to remove the tarnish therefrom.v -In theaggregate, the expense and the amount of work involved in overcomingvsuch objectionable tarnishing form a considerable part of the lexpenseand labor lofl taking care of such silverware displays. The problem ispresented in a some- 'what similar manner with other metal articles,made of other metals .than silver, and is a problemlwith whichv thehousewife is confronted wherever silverware is displayed or exposed tothe air, since even the air of lthe home, particularly in large citiesand where the atmosphere is smoky, contains a lApplication filed. April23, 1924. Serial No. 708,354.

sufficient amount of sulfur-containing constituents to cause tarnishinglof silverware after varlying periods of time. This tarnishlng of s1 ver,etc. seems to be occasioned not by sulfur-containing compounds alone,but by such compounds when moisture is also present. In a completelyanhydrous atmos` phere, even considerable amounts of sulfurcontainingconstituents in the air may be without objectionable tarnishing effect,even after prolonged periods of time. Moreover, apparentlySulfur-containing gases and particles in the air have an affinity formoisture, such that moist air, when laden with sulfurcontaining gases,appears to be much more objectionable because of its tarnishingprospensity. f'

Because of the heat conducting properties of metals, -metal surfacesafford attractive surfaces. for the condensation of moisture thereon.If, for example, the air is warmer than the metal Surface, the coolermetal surface will tend to condense moisture from the air immediatelyadjacent to it, and there will tend to be formed an adsorbed or absorbedilm of moisture on the metal surface. It is perhaps for this reason thatsulfur- .containing gases are so objectionable when moisture is present,for if the moisture which is condensed on the metal surface carriessulfur-containing gases which are condensed with it, these gases canthen attack'the silver or. other metal surface in the presence ofsuiiicient moisture to permit the formationof a black film of silversulfide,

nishing is due.

The present invention provides an improved anti-tarnish composition, and.improved articles or structures embodying or to the formation of whichobjectionable tar'` combined with such anti-tarnish composition, wherebyobjectionable tarnishing of silver, etc. can be prevented for longperiods of'time, in a particularly effective manner.

It is well known that aqueous solutions of different metal salts, whenbrought into contact with hydrogen sulfide and other sulbecomes Aoflittle or no value. Moreover, if

water .is present considerable amount inv Show-casesand Similar `placeswhere jewelry and sllverware are .commonly kepton dlshydrogen sulfide,etc. from the air which comes in contact with them, but I avoid aqueoussolutions of such salts, and, 1n-

stead, I use solutions of such salts innon-l volatile solvents which aremoreover hygroscopic and which tend .to remove moisture from the air ofthe show-case or other place, as wellas the sulfur-containing compoundswhich the air contains.

I have found that the objections and limitations of aqueous solutions ofsuch metal salts can be overcome, and new' and advantageous resultsobtained, by dissolving the metal salts in a non-volatile solvent suchas glycerine, etc., in which the metal salt is soluble, and whichitselfv has hygroscopic properties or an affinity for 'water-vapor andwater. The new composition of the present invention, accordingly, is asolution of a metal salt, such as lead acetate, in a non-volatilesolvent, and particularly in such a solvent which has hygroscopicproperties.

Different metal salts may be used in the composition of the inventionbut I have found that lead acetate is particularly effective. 4Otherlead salts, however, can be used and even salts of other metals.

The solvents which are used may contain some water, but I have found itadvan- 'tageous for best results to use a solvent which is free orrelatively free from water, such as a polyhydric or polyhydroxyderivatives, especially glycerine, although other compounds such asglycols can be used,'or even aqueous solutions of glucose. Glycerine notonly has the property of dissolving lead acetate, for example, but inview of its hygroscopic properties, it tends to attract moisture fromthe air, and, in this way, when exposed to the air, tends not only toremove sulfur compounds such as sulfurated hydrogen, but also to keepthe air' dry. Since the' particles of sulfur compounds tend to associatethemselves with and to deposit on the particles of water'f'vapor in theatmosphere, the presence of a substance such as a glycerine solution ofthe metal-salts tends to draw to it the particles of water-vapor withthesulfur particles attached thereto so that the sulfur particles reactwith the metallic salts dissolved in the glycerine to form a metallicsulfide, instead of condensing on the metal surface and tarnshing themetal.

The 'new composition, containing the metal salts dissolved'in anon-volatile sol# vent, can be used in various ways. One advantageousapplicationof the composition is for impregnating a fabric to provide'an pounds is exposed to the impregnated ma- 4 terials. Absorbentmaterials such as kieselguhr may be used to absorb the solution.l

I have found that compositions containing the lead acetate dissolved inglycerine are radically more effective than lead acetate when used inwater solutions, wherethe water tends to evaporate and leave a dryresidue ofthe lead acetate.

The nature and advantages of the inven tion will be further illustratedby the following examples and more detailed description.

One composition which I have found most satisfactory is made bydissolving lead acetate in glycerine in the proportion of about 1 lb. oflead acetate to'l pint of glycerine without the addition of any waterthereto. The dissolving .of the lead acetate in the glycerine lcanadvantageously be carried out by placing for example 5 gallons ofglycerine (using'either chemically pure yellow distilled glycerine or acrude glycerine) in a copper tank, heating to about 155 F., then addingthe powdered lead acetate, and stirring until the lead acetate isdissolved. After the leadv acetate is dissolved, the temperature of thesolution can be lowered to.

about 130 F., but for the impregnation of fabric, etc., the temperatureshould not be permitted to drop below about 100 F., as the solutionbecomes too thick to use readil if it is cooled below approximatelysuoli temperature.

In -kusing such a solution for the impregnation of fabrics, a pad offelt; or other fabric can be dipped in the solution while heated to atemperature above 100 F., e. g. around 130 F., and the impregnatedfabric can then be passed through a wringer. The pads, particularly ifmade of porous material such as felt, can' then be hung up for a periode. g. of about 48 hours to -allow the excess solution to drip oit fromInstead of using glycerine alone for d'rsy l solving 'the lead acetate,I have also used an aqueous glycerine solution containing vary-v ingproportions of water and glycerine. For example, a 25 per cent solutionof glyc- .solved without the necessity of using such high temperaturesas referred to in the preceding example. d

In Iusingsuch an aqueous glycerine solution for treating felt pads orfabrics, the

' p-ads can be dipped in the solution,r then Y Il, themselves containobjectionable sulfuf coin.

ypleted by hot air-"or -ina tumbling wrung and then dried in a blast ofhot air to remove the water and leave the glycerine' solution of thefabric.

For certain purposes, I find it more adif'antageous t-o use a still moredilute mixture, containing, for example, 1 pint of `glycerine in eachga.llon,'or'even less glycerine, and 2 lbs. faceta't'e of lead pergallon; Such a solution can advantageouslybebsed for treating boxlinings, curtains and other y.ina-

the lead acetate impregnating terial which may come in direct contactwithy the silver. Box linings for examplegmay be dipped in the solution,then wrung out, and then put in a rotating extractor `to`removemoisture, and the drying may then be combarrel heated by a hot airblast. y

The composition can be used for rendering materials anti-tarnishingwhere they pounds. l Where, for example, paper, string and otherlsubstances', or` material suoli as glue, which areused with silverwareand tarnishable metals, are to be rendered antitarnishable, they may beanalyzed to determine their sulfur content, and they may then be treatedby the .composition of the present inv'ention'to destroy theirtarnishing properties, so that they can then be used without danger ofcausing tarnis-hing of the silverware or other articles with which'theycome' 'in contact.

The formulae and compositions referred to above,y and the specialmethods of'their application, are typical and illustrative of theinvention. The particular proportions' of the ingredients, and thenature ofthe formulae, can be varied somewhat care of varyingconditions.

,Instead ofusing fabrics for carrying the composition, cardboard padsmay someto take times be used, the pads being dipped, wrung and thenplaced in a wooden rack with air space and allowed to dry forasufficient time. Where the composition contains water,y and the fabricor other-'material is impregnatedwifth it, the excess water can besubsequently removed by heating to a sufficient temperature for asuitable periodV of time.

l Y Where the glycerine Iis used alone without for example be from 130F. to 17 5 F., a

though I have found a temperature of about 155"l F. to be suitable formaking a solution to be subsequently used for impregnating the fabric inthe manner described.

In protecting show-cases and 'the like I have found it` advantageous Itouse a feltpad of appreciable thickness impregnated with the newcomposition. Other fabrics or other absorbent material can however beused, such as cotton, paper, wool, wicking, charcoal, hemp, kieselguhr,etc. Feltpads, however, have an appreciable thickness and oa'n retain aconsiderable amo-unt of the composition so that they are effective o-verrelatively long periods of time. The felt pads may advantageously beplaced in pad holders or frames so that they caribe readily handled, andthese frames can advantageously be attached to the under side of theshelves of the show case or cabinet so, as

to take up a minimum amount of room in ther show-case, and so as not tointerfere with the display of merchandise in the showcase. Asdistinguished from a dry fabric,

the impregnated pad or fabric of the prese-nt'invention, where itcontains a considerable amount of they composition of the 1nvention, hasa somewhat -moist feel, and

some of the composition may be rubbed off containers can be used inwhich an `absorbent material .is treated with the composition and storedin such a way as to come in'contact with the air which the containerholds. Such a container may have holes in it which will allow the airtoenter, so..y that, through these holes, the air has laccess to thecomposition and can come in contact with the treated absorbent material.Bowls containing the anti-tarnish composition of the invention can alsobe used together with a wick-like substance such as hemp or charcoalwhich will serve -to present to the air an extended tion. y

The use of the new composition of the invention when properlydistributed and exposed to the atmosphere of a show case and the like,provides a novel and improved method for purifying the air oftheshouopened by people entering and leaving the store., and where theshow-case is being more or less frequently opened for the display ofmerchandise, to wash the air or purify it so surface carrying thecomposii that the air contained lin the storeand inA which has an athntyfor moisture. In the processof the invention`,accordingly, and

in using ,the composition of the invention, .the air is. subjected to acombined drying :and desulfurizing treatment by acomposltion which hasan absorptive attraction for both moisture and sulfur-containing vapors-This puriiication of the air serves to protect the silverware and othermetal articles' from tarnishing because the moisture andsulfur-containing vapors which would otherwise tend to separate out onthe metal surfaces are instead attracted to the hygroscoplc andsulfur-compound-neutralizing composition of the invention. Since a sul-Afur-containing gasv naturally tends to deposit on, or dissolve in,Water' vapor, and since the latter is in turn attracted to, and held by,the composition of the invention, particularly when distributed over thesurface of a pad or other material, it may be said that the compositionof the invention exerts a preferential aflinity for moisture and forsulfur-containing vapors, and consequently brings about an e'ectiveremoval of sulfur-vapors and of moisture from the air, and therebyprotects the silverware and other metal objects from tarnishing.

The advantages of both drying the air and absorbing sulfur-containingases, as 'compared with absorbing sulp ur-containing gases withoutdrying the air, or absorbing ,certain gases by solutions. whichincreases lthe humidity of the air, will be appreciated when it isconsidered that dry gasesl such as hydrogen sulfide do not react readilywith, or bring about, a tarnishing of metals, while the presence ofmoisture promotes such tarnishing When such sulfur-containing comundsare present. lhe composition of the invention may therefore beconsidered to prevent or retard tarnishing by keeping the air d as Wellas by absorbing .the objectionab e sulfur-containing gases and com-Vpounds and thus protecting the metal surfaces 'from them.

In the commercial application of the invention, the particulanform inwhich the composition, or articles carryin or impregnated by thecomposition, will used will vary with the conditions where thecomposition is to be used. By coatin a wood or other surface with thecomposition, the composition can beapplied without the use of a fabricor similar absorbent. For eX ample, the under side of a shelf in a`showcase, if adapted for holding a coating of the com-position, can diepainted or coated with the compositionand this composition Will protectthe air of the show-case and the silver articles in the show-case forconsiderable periods of time'. A porous board of Wood or otherl materialcan similarly be painted with the composition and hung up position of,the invention.

Fig. 2 shows such a pad supported in a frame.

Fig. 3 shows a further method of supporting such a pad.

F ig. 4 shows still a further method of supporting the pad, and

Fig. 5 illustrates a show-case with the mvention embodied therein. A

The pad of Figs. 1 4y may be a felt pad. dyed black for example andimpregnated with the composition of the invention, for example,according to the lirst speclic example hereinbefore given.

Figs. 2, 3 and 4 show various methods of supporting and holding the padin a frame or support. In Fig. 2 the pad 1 is held between a top member2 which may be a thin board or cardboard, and a bottom ,frame member 3`which holds the edges of the pad. In Fig. 3, the upper member 4 may bean ordinary board or cardboard and the lower member 5 is a perforatedboard or cardboard having perforations permitting the access of air tothe4 impregnated pad. These membersmay be held togetherv in any suitableway. Inl Fig. 4 the pad 1 is held betweenthe upper member 6 and theframe member 7 anda screen 8.is provided for assisting in 'supportingthe pad .while permitting access of the air thereto. l

Pads of this kind can be supported as indicated at '14, 15 and 17 inEig. 5,fattached to the under side of the shelves 12 and 13 or to thedoors of the cabinet 9 having front and top glass members 10 and 11 anddoors at the back for permitting access to the cabinet or show-case. Apad 16 is shown as supported in the upper portion of the showcase or 4cabnet,.this pad vbeing merely depending-and supporte-d at its upper end,or being a wick-like .structure and having one end depending into acontainer containing the composition. y

In suc-h a. show-case, the air within the show-case, while relativelyquiscent, is nevertheless more or less in motion, while the opening o-fthe door permits access of .fresh alr from outside'and also serves tostir up and set in motion the air within the showcase. In such ashow-case, however, 'the pad containing the composition of the inventionlWill exert its hygroscopic action upon the air and will tend to keep itdry, while the metal salt in solution will be exposed in a reactivestate to the air in the show-case and the sulphur-containing compoundswill be attracted the-reto and will be absorbed and held thereby. Thehygroscopic nature of the glycerine 'solvent promotes the reaction o fthe. sulphur compounds contained in the air with the lead salt, both byattracting moisturelwhich assists inthe reaction, and by attractingmoisture which may already have combined with and which carries thesulfur-containing compounds themselves.

It will thus be seen that the present invention provides 'an improvedcomposition as well as a felt pad or other absorbent materialimpregnated therewith or treated there- With, and structures such asshow-cases, cabinets, etc. in which the composition is provided toprotect the structures and particularly to protect the silverware andtarnishable metal articles therein. It willv further be seen that theinvention pro-vides an improved method of making the composition aswellas an improved method of using the composition and of saturating ortreating fabrics and other materials therewith, and

an improved method of protecting jewelry, silverware, etc. fromtarnishing and for purifying the air of show-cases and other structuresfrom sulfur-containing constituents having tarnishing propensities. K y

The novel composition of the invention, as

. hereinbefore pointed out, contains a metal salt such asv lead acetate,dissolved in a` solvent which is non-volatile and which has vhygroscopicproperties', which solution is used for treating or saturating orimpregnating various fabrics or absorbent mate- Lrials to giveprotective surfaces which when exposed to the air will serve topurifythe air in the manner hereinbefore described.-

I claim:

1. .A new anti-tarnish composition -comprisingl a solution of a metalsalty capable of absorbing hydrogenlsulfide ina hygroscopic non-volatilesolvent.

2. A new anti-tarnish composition` comprising a solution of a metal saltcapable of absorbing hydrogen sulfide `in a poly-hydroxy compound.

3. A new anti-tarnish composition comprising a solution of lead' acetatem glycerlne.

. 4. The method of making an anti-tarnish i Icomposition which comprisesdissolving lead 1- acetate in glycerin@ at an 'elevated temperature,

5. A new article or composition comprismg an absorbent material carryinga solution of a metal salt-capable of absorbing hydrogen sulfide inayhygroscopic organic solvent.

6. A new articlev or composition comprising an absorbent materialcarrying a solution of lead acetate in glycerine.

7. A fabric impregnated with a composition comprising a metal saltcapable of absorbing hydrogen sulfide and a hygroscopic organic liquid.

8. A fabric impregnated with an anti` solvent and a support forsupporting said l absorbent material so as to expose the antitarnishcomposition to the air.

` 10. A fabric impregnated with a solution of lead acetate in glycerine,said fabric having a supporting frame or support.

11. A show-case or similar structure having therein, exposed .to the airtherein, an anti-tarnish composition which is both hygroscopic andcapable of absorbing sulfurcontaining constituents from the air.

12. A show-case or similar structure for containing silverware and thelike, having. therein an extended surface, carrying a hygroscopiccomposition containing a netal salt capable of absorbing hydrogensulfide, said composition being capable of absorbing both moisture andsulfur-containing constituents from the air. r

13. A show-case or other structure adapted for containing silverware andthe like, the interior of such structure having an extended surface incontact with the air of the i show-case, which surface carries asolution of a metal salt capable of absorbing hydrogen sulfide in ahygroscopic organic solvent.

14. A show-case or other Structure adapted for containing silverware andthe like, the interior of such structure having an extended surface incontact with the air of the show-case, which surface carries a solutionof lead acetate in glycerine. I

15. A show-case or other structure adaptedk for containing silverwareand the like, said structure having therein a fabric exposed to the airand which fabric carries a composition comprising lead acetate andglycerine, said composition being hygrcscoplc and capable of absorbingboth moisture from the lair and sulfur-containing compounds from droxyorganic solvent at au elevated teraglycerine, treating an absorbentmaterialV with such solution, and drying the-resulting product to removewater therefrom.

18. `The method of preparing an anti-tarnish fabric which comprises`treating the fabricl at an elevated tem erature with ra non-aqueoussolution of lea acetate in glycerine, and removing the excess of thesolution.

19. The method of preparing an anti-tarnish fabric which comprisestreating the fabric with a solution of lead acetate in aqueousglycerine, and subsequently drying the fabric to remove water therefrom.

20. The method of preparing an anti-tarnish fabric which comprisesdlssolving lead acetate in an aqueous solution of glycerine.

vtreating Ithe fabric with such solution, re-

moving the excess of such solutiony and drying the fabric to removeWater therefrom.

21. The method of purifying air in showcases and similar structures forthe protection of silverware and the like from tarnishing,.whichcomprises sub'ecting the air in such structures to the puri ing actionof a hygroscopic composition containing a metal salt capable ofabsorbing hydrogen sulfide, said composition being adapted to absorbmoisture from the air and also to absorb sulfur-containing constituentsfrom the air.

22. The method of purifying the air in show-cases and the like for theprotection of jewelry, etc. from tarnishing, which comprises subjectingthe air in such structures to` the purifying action of a solution oflead acetate in glycerine, said solution being hygroscopic and absorbingmoisture from the air and also absorbing sulfur-containing constituentsfrom the air.

In testimony whereof I aflix my signature.

'rHoMA-s HOLMES LASHAR

